Cryogenic ground supporting equipment (CGSE) developed for international cooperation scientific experimental item AMS-02 is the ground supporting and cooling system, which will complete the cooling process of the supe...Cryogenic ground supporting equipment (CGSE) developed for international cooperation scientific experimental item AMS-02 is the ground supporting and cooling system, which will complete the cooling process of the superconductor of AMS-02 from ambient temperature to 1.8 K. Obtaining 1.8 K He Ⅱ by vacuum-pumping is discussed in detail and compared with the other three schemes. The results show that the scheme of vacuum-pumping not only could meet the requirement of the project much better but also has higher reliability compared with other schemes. To select the vacuum pump, the energy conservation model is presented according to the experimental system of CGSE. Therefore, the pumping speed is also determined.展开更多
The temperature rise of He Ⅱ transfer system due to the negative Joule-Thomson(JT)effect is one of the major problems in the He Ⅱ forced flow system design.Negative Joule-Thomson effect of the He Ⅱ forced flow was ...The temperature rise of He Ⅱ transfer system due to the negative Joule-Thomson(JT)effect is one of the major problems in the He Ⅱ forced flow system design.Negative Joule-Thomson effect of the He Ⅱ forced flow was analyzed and calculated in this paper.The temperature rise due to the heat leak along the transfer pipeline was calculated by the simplified equation and was modified by considering the negative Joule-Thomson effect.The modified results were compared with the temperature rise obtained by non-linear differential equations with consideration of the pressure gradient.The results show that the pressure gradient has strong effect on the temperature distribution.The modified results are in good agreement with the values calculated by the complicated equation,which verifies the effectiveness of the simplified equation in calculating the temperature rise when the negative JT effect of He Ⅱ is known.展开更多
基金The National Natural Science Foundation of China ( No. 50476022 )Ministries and Commissions of Science and Technology of Shanghai Government (No. 03DZ 14014)
文摘Cryogenic ground supporting equipment (CGSE) developed for international cooperation scientific experimental item AMS-02 is the ground supporting and cooling system, which will complete the cooling process of the superconductor of AMS-02 from ambient temperature to 1.8 K. Obtaining 1.8 K He Ⅱ by vacuum-pumping is discussed in detail and compared with the other three schemes. The results show that the scheme of vacuum-pumping not only could meet the requirement of the project much better but also has higher reliability compared with other schemes. To select the vacuum pump, the energy conservation model is presented according to the experimental system of CGSE. Therefore, the pumping speed is also determined.
基金Sponsored by the National Natural Science Foundation of China(Grant No.10872152)the Ministries and Commissions of Science and Technology of Shanghai Government (Grant No. 03DZ 14014) for Shanghai Jiaotong University
文摘The temperature rise of He Ⅱ transfer system due to the negative Joule-Thomson(JT)effect is one of the major problems in the He Ⅱ forced flow system design.Negative Joule-Thomson effect of the He Ⅱ forced flow was analyzed and calculated in this paper.The temperature rise due to the heat leak along the transfer pipeline was calculated by the simplified equation and was modified by considering the negative Joule-Thomson effect.The modified results were compared with the temperature rise obtained by non-linear differential equations with consideration of the pressure gradient.The results show that the pressure gradient has strong effect on the temperature distribution.The modified results are in good agreement with the values calculated by the complicated equation,which verifies the effectiveness of the simplified equation in calculating the temperature rise when the negative JT effect of He Ⅱ is known.
